OA of the knee is a significant problem in later life, which is associated with declines in functional capacity. This chronic condition is accompanied by increasing degrees of knee pain, which is associated with decreasing levels of functional capacity. The increasing incidence of total knee arthroplasty (TKA) appears to indicate that conservative approaches have limited effectiveness in relieving symptoms of OA of the knee. Recovery following TKA surgery appears empirically and theoretically positively linked to functional capacity prior to surgery. A large number of investigators have indicated that various exercise interventions can improve the functional capacity of knee OA patients. To date no study has yet demonstrated the efficacy of preoperative exercise training, which improves functional capacity, on the postoperative recovery of TKA patients. Preliminary studies in the area indicate the feasibility of TKA patients engaging in various types of exercise interventions preoperatively. These studies have been limited by a number of methodological flaws, which may have contributed to their inconclusive findings that preoperative exercise had no effect on postoperative recovery among TKA patients. The proposed study will address these flaws by utilizing an urger sample and employing proven exercise interventions, which have been shown to improve the functional capacity of patients with OA of the knee. The specific aim of this study is: to compare the knee pain, ability to complete functional tasks and markers of prehabilitation among TKA patients who do and do not participate in an 8-week program of prehabilitation prior to their FKA surgery. To address this aim ninety-eight community dwelling subjects age 50 and older who are scheduled for a unilateral TKA will be recruited from a single orthopedic surgeon's practice. Subjects will be assessed prior to beginning interventions at baseline, one week prior to their TKA surgery, and 1 and 3 months following their TKA surgery. These assessments will include measures of knee pain, the ability to complete functional tasks and markers of rehabilitation. Following baseline-testing subjects will be randomized into either a prehabilitation group (treatment) or a usual treatment group (control). Subjects in the treatment group will participate in three sessions of prehabilitation per week, one supervised and 2 unsupervised, for eight weeks prior to their TKA. The training will consist of resistance training, flexibility exercises and step training. The three principle hypotheses of this study will be tested through repeated measures analysis of covariance. This statistic compares the two groups' dependent outcome measures at, one week prior to their TKA and 1 and 3 months following the TKA procedure while adjusting for dependent measures taken at baseline and potential confounding variables between the groups. The outcomes of this study have the potential to reveal that preoperative exercise can enhance post surgical recovery.